Malicious Office (OLE) / .XLSX — malware analysis report

Static analysis result for SHA-256 4cf69fcd51e8e379…

MALICIOUS

Office (OLE) / .XLSX

565.5 KB
MD5: 1192eee111cf7fb2f9a5298d229672c0 SHA-1: 5ead532038b1c5b7e719d9d8c91889891121353c SHA-256: 4cf69fcd51e8e379798c07df4c11cd38e4f7203d3493d76ecebce0fb25c9532a
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an encrypted OOXML file containing an Equation Editor OLE object. High-severity heuristics indicate the presence of CVE-2018-0798, a vulnerability in Equation Editor, suggesting the file is designed to exploit this flaw for initial execution. No document body or scripts were extractable due to encryption, but the presence of the exploit carrier strongly implies a payload delivery mechanism.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Default-encrypted OOXML embedded OLE object xl/embeddings/oleObject1.bin contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • CVE-2018-0798 — anomalous Equation Editor native stream high CVE likely CVE_2018_0798_EQUATION_NATIVE_ANOMALY
    Default-encrypted OOXML contains embedded Equation Editor data with anomalous native stream bytes consistent with a CVE-2018-0798-style exploit. This is treated as likely CVE evidence because the Equation object is malformed and payload-like.
  • Default-encrypted OOXML exploit carrier layout high OOXML_ENCRYPTED_EXPLOIT_CARRIER_SHAPE
    Default-password encrypted OOXML package contains embedded OLE object parts and additional activation/decoy parts. This layout is common in malicious Excel exploit delivery and requires inspecting the decrypted package.
  • Office OOXML encrypted with default VelvetSweatshop password medium OFFICE_DEFAULT_PASSWORD_ENCRYPTED_OOXML
    OLE EncryptedPackage decrypts with Excel's built-in VelvetSweatshop password. Office opens this transparently, and malware uses it to hide OOXML exploit parts from scanners that only inspect the outer OLE container.